This map was created by the Mississippi River Commission (MRC) in the 1890s.  The MRC maps of the Mississippi River are a valuable resource for archaeologists working in the Mississippi Valley because they show the landscape and vegetation of the valley prior to damming.  At this time, Spring Lake was still a very small lake, separated from the main channel of the Mississippi and surrounded by marshland.  However, Spring Lake didn’t exist at all until the 1850s.  Sometime in the 1850s, the tributary stream south of the main channel was dammed at its mouth to power a small mill.  This mill dam is what created historic Spring Lake.  Before that, the whole area was a very big marsh fed by numerous natural springs.  

We also know from historic sources that the island area between the main channel of the Mississippi and the small tributary, part of which can be seen at the top of this image, was an important gathering place for American Indian communities in the area.  This island, and many others, are now under the water of modern-day Spring Lake.